1. Field of the Invention
The present invention relates to a process to operate a reel winding device having at least two drive mechanisms acting on a material web roll with different driving forces during winding. In addition, the invention relates to a reel winding device having at least two drive mechanisms acting on a roll, and to a measuring device to be utilized in conjunction with the process and/or apparatus.
A reel winding device can be formed, for example, by a two-drum winder which is used to wind a material web into a wound roll. Alternatively, it can be formed by a contact roll winder in which the roll is driven both centrally by a center drive as well as by a contact roll on its circumference. The contact roll can also be embodied as a backup roll and take on at least a portion of the roll weight.
2. Discussion of Background Information
It has now been found that, when starting up reel winding devices, for example, it takes a relatively long time until both drives of the winding rolls are adjusted so that the desired winding tension and, thus, the desired winding tightness progression has been generated in the wound roll. Many problems also arise during operation that can only be alleviated by trial and error in adjusting the drive power for the individual winding rolls. The situation is complicated in that when transitioning from one material, i.e., from one type or quality, to another, different winding ratios are very often required so that one must practically run new attempts or trials for every type of material. Since the designer and the operator of reel winding devices only have limited opportunities to control the function of the king roll drives, most of the time a safe possibility is lacking for checking conformity between the preset target curves and the actual values for the peripheral force difference as a way of influencing winding tightness on the wound roll. Once there is a guarantee that the preset target curves are actually still being run, it becomes possible to begin optimizing roll quality and eliminating winding errors.
Determining the king roll peripheral forces from the electrical drive power, i.e., motor current and motor voltage, the efficiency levels of the motor and any gears that are present, and the geometric conditions, such as diameter of the winding rolls, web speed and the like is not exact enough, particularly in the acceleration phase. Even information about the efficiency of the motor and the gear is oftentimes not exact enough.